1. Field of the Invention
The field of this invention is polyether ester amides and their use.
2. Description of Related Art
Thermoplastic elastomers (TPE) are a class of polymers which combine the properties of two other classes of polymers, namely thermoplastics which may be reformed upon heating, and elastomers which are rubber-like polymers. One form of TPE is a block polymer, usually containing some blocks whose polymer properties usually resemble those of thermoplastics, and some blocks whose properties usually resemble those of elastomers. Those blocks whose properties resemble thermoplastics are often referred to as xe2x80x9chardxe2x80x9d segments, while those blocks whose properties resemble elastomers are often referred to as xe2x80x9csoftxe2x80x9d segments. In such TPEs, the hard segments are believed to take the place of chemical crosslinks in traditional thermosetting elastomers, while the soft segments provide the rubber-like properties. Improved thermoplastic elastomers, particularly those with improved elastomeric properties such as high tenacity, elongation and unload power, and low tensile set, have been desired for use in fibers and other shaped articles.
Polyether ester amide block polymers prepared from polyether glycol and polyamide with carboxyl end groups are known. These polymers have been prepared using polyethylene glycol, polypropylene glycol, polytetramethylene glycol, copolyethers derived therefrom, and copolymers of THF and 3-alkylTHF as shown by U.S. Pat. Nos. 4,230,838, 4,252,920, 4,349,661, 4,331,786 and 6,300,463, all of which are incorporated herein by reference. The general structure may be represented by the following formula (I): 
represents a polyamide segment containing terminal carboxyl groups or acid equivalents thereof (e.g., diacid anhydrides, diacid chlorides or diesters) and
xe2x80x94Oxe2x80x94Gxe2x80x94Oxe2x80x94xe2x80x83xe2x80x83(III)
is a polyether segment.
Poly ether ester amides prepared using poly(ethylene glycol) have the disadvantage that they absorb considerable amounts of moisture. Polypropylene glycol as described in the aforementioned patents refers to the polyether glycol derived from 1,2-propylene oxide. Polymerizations using polypropylene glycol generally proceed slowly due to the presence of sterically-hindered secondary hydroxyl groups. The extended periods of time for which these polymers are held at elevated temperatures can lead to thermal decomposition and discoloration. Polytetramethylene ether ester amide block polymers are easy to prepare, and thus they have been used to prepare fibers with elastomeric properties. Polyether ester amide elastomers derived from copolymers of tetrahydrofuran (THF) and 3-methylTHF are relatively new and have been found to have excellent physical properties, particularly high unload power and elastic recovery (lower tensile set) after stretching.
None of the aforementioned patents describe preparing polyether ester amide elastomers from polytrimethylene ether glycol. It has unexpectedly been found that polytrimethylene ether ester amides provide improved elastomeric properties over polytetramethylene ether ester amide block polymers and polyether ester amide elastomers derived from copolymers of tetrahydrofuran (THF) and 3-methylTHF. Particularly noteworthy are improvements in elongation and tensile set.
The invention is directed to polytrimethylene ether ester amide and its use.
The polyamide segment preferably has an average molar mass of at least about 300, more preferably at least about 400. Its average molar mass is preferably up to about 5,000, more preferably up to about 4,000 and most preferably up to about 3,000.
The polytrimethylene ether segment has an average molar mass of at least about 800, more preferably at least about 1,000 and more preferably at least about 1,500. Its average molar mass is preferably up to about 5,000, more preferably up to about 4,000 and most preferably up to about 3,500.
The polytrimethylene ether ester amide preferably comprises 1 up to an average of up to about 60 polyalkylene ether ester amide repeat units. Preferably it averages at least about 5, more preferably at least about 6, polyalkylene ether ester amide repeat units. Preferably it averages up to about 30, more preferably up to about 25, polyalkylene ether ester amide repeat units.
At least 40 weight % of the polyalkylene ether repeat units are polytrimethylene ether repeat units. Preferably at least 50 weight %, more preferably at least about 75 weight %, and most preferably about 85 to 100 weight %, of the polyether glycol used to form the soft segment is polytrimethylene ether glycol.
The weight percent of polyamide segment, also sometimes referred to as hard segment, is preferably at least about 10% and most preferably at least about 15% and is preferably up to about 60%, more preferably up to about 40%, and most preferably up to about 30%. The weight percent of polytrimethylene ether segment, also sometimes referred to as soft segment, is preferably up to about 90%, more preferably up to about 85%, and is preferably at least about 40%, more preferably at least about 60% and most preferably at least about 70%.
The polytrimethylene ether ester amide comprises polyamide hard segments joined by ester linkages to polytrimethylene ether soft segments and is prepared by reacting carboxyl terminated polyamide or diacid anhydride, diacid chloride or diester acid equivalents thereof and polyether glycol under conditions such that ester linkages are formed. Preferably it is prepared by reacting carboxyl terminated polyamide and polyether glycol comprising at least 50 weight %, more preferably at least 75 weight %, and most preferably about 85 to 100 weight %, polytrimethylene ether glycol.
In one preferred embodiment the carboxyl terminated polyamide is the polycondensation product of lactam, amino-acid or a combination thereof with dicarboxylic acid. Preferably, the carboxyl terminated polyamide is the polycondensation product of C4-C14 lactam with C4-C14 dicarboxylic acid. More preferably, the carboxyl terminated polyamide is the polycondensation product of lactam selected from the group consisting of lauryl lactam, caprolactam and undecanolactam, and mixtures thereof, with dicarboxylic acid selected from the group consisting of succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, and isophthalic acid, and mixtures thereof. Alternatively, the carboxyl terminated polyamide is the polycondensation product of amino-acid with dicarboxylic acid, preferably C4-C14 amino-acid and preferably C4-C14 dicarboxylic acid. More preferably, the carboxyl terminated polyamide is the polycondensation product of amino-acid selected from the group consisting of 1 -amino-undecanoic acid and 12-aminododecanoic acid, and mixtures thereof, with dicarboxylic acid selected from the group consisting of succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, and isophthalic acid, and mixtures thereof.
In another preferred embodiment, the carboxyl terminated polyamide is the condensation product of a dicarboxylic acid and diamine. Preferably, the carboxyl terminated polyamide is the condensation product of a C4-C14 alkyl dicarboxylic acid and C4-14 diamine. More preferably, the polyamide is selected from the group consisting of nylon 6-6, 6-9, 6-10, 6-12 and 9-6.
Preferably the polytrimethylene ether ester amide has a general structure represented by the following formula (I): 
represents a polyamide segment containing terminal carboxyl groups or acid equivalents thereof, and
xe2x80x94Oxe2x80x94Gxe2x80x94Oxe2x80x94xe2x80x83xe2x80x83(III)
is a polyether segment, and X is 1 up to an average of about 60, and wherein at least 40 weight % of the polyether segments comprise polytrimethylene ether units. (A and G are used to depict portions of the segments which are ascertained from the description of the polytrimethylene ether ester amide and starting materials.)
Preferably the polytrimethylene ether ester amide of claim 1 has the general structure represented by the above formula (I) where (II) represents a polyamide segment containing terminal carboxyl groups or acid equivalents thereof, (III) is a polytrimethylene ether segment, and X is 1 up to an average of about 60.
The invention is also directed to shaped articles comprising the polytrimethylene ether ester amide. Preferred shaped articles include fibers, fabrics and films.
The invention is directed to polytrimethylene ether ester amide and its use.
Polytrimethylene ether ester amides can be thought of as comprising polyamide hard segments or blocks joined by ester linkages to polyether soft segments or blocks. Thus, they are sometimes referred to as block polymers. They are prepared by reacting carboxyl terminated polyamide (or acid equivalents thereof) and polyether glycols.
Herein, when referring to the polytrimethylene ether ester amide, carboxyl terminated polyamide or acid equivalents thereof, polytrimethylene ether glycol, etc., it should be understood that reference is to one or more of these items. Thus, for instance, when referring to at least 40 weight % of the polymeric ether glycol used to form the soft segment being polytrimethylene ether glycol, it should be understood that one or more polytrimethylene ether glycols can be used.
The general structure of polytrimethylene ether ester amides can be thought of with reference to formula (I) where (II) represents a carboxyl terminated polyamide (or acid equivalent thereof) segment, and (III) is a polyether segment at least 40 weight % of which is from polytrimethylene ether glycol and is referred to herein as a polytrimethylene ether segment (it may also be referred to as a xe2x80x9cpoly(trimethylene oxide) segmentxe2x80x9d).
The polyamide segment preferably has an average molar mass of at least about 300, more preferably at least about 400. Its average molar mass is preferably up to about 5,000, more preferably up to about 4,000 and most preferably up to about 3,000.
The polytrimethylene ether segment preferably has an average molar mass of at least about 800, more preferably at least about 1,000 and more preferably at least about 1,500. Its average molar mass is preferably up to about 5,000, more preferably up to about 4,000 and most preferably up to about 3,500.
The polytrimethylene ether ester amide contains at least 1 polyether ester amide repeat unit. It preferably comprises up to an average of up to about 60 polyalkylene ether ester amide repeat units. Preferably it averages at least about 5, more preferably at least about 6, polyalkylene ether ester amide repeat units. Preferably it averages up to about 30, more preferably up to about 25, polyalkylene ether ester amide repeat units.
The weight percent of polyamide segment, also sometimes referred to as hard segment, is preferably at least about 10% and most preferably at least about 15% and is preferably up to about 60%, more preferably up to about 40%, and most preferably up to about 30%. The weight percent of polytrimethylene ether segment, also sometimes referred to as soft segment, is preferably up to about 90%, more preferably up to about 85%, and is preferably at least about 40%, more preferably at least about 60% and most preferably at least about 70%.
Carboxyl terminated polyamides or acid equivalents thereof, such as diacid anhydrides, diacid chlorides or diesters, useful in preparing the polytrimethylene ether ester amides of this invention are well known. They are described in many patents and publications related to the manufacture of other polyalkylene ester amides, such as U.S. Pat. Nos. 4,230,838, 4,252,920, 4,331,786, 4,349,661 and 6,300,463; all of which are incorporated herein by reference.
Preferred polyamides are those having dicarboxylic chain ends and most preferred are linear aliphatic polyamides which are obtained by methods commonly used for preparing such polyamides, such as processes comprising the polycondensation of a lactam, an amino-acid or a diamine with a diacid, such as described in U.S. Pat. No. 4,331,786, which is incorporated herein by reference.
Preferred polyether ester amides are those in which the carboxyl terminated polyamide poly amide was derived from the polycondensation of lactams or amino-acids with a dicarboxylic acid. The dicarboxylic acid functions a chain limiter and the exact ratio of lactam or amino-acid to dicarboxylic acid is chosen to achieve the final desired molar mass of the polyamide hard segment. Preferred lactams contain 4-14 carbon atoms, such as lauryl lactam, caprolactam and undecanolactam. Most preferred is lauryl lactam. Preferred amino acids contain 4-14 carbon atoms and include 11-amino-undecanoic acid and 12-aminododecanoic acid. The dicarboxylic acid can be either linear aliphatic, cycloaliphatic, or aromatic.
The preferred dicarboxylic acids contain 4-14 carbon atoms. Examples include succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, and isophthalic acid. Most preferred are the linear aliphatic dicarboxylic acids, especially adipic acid and dodecanedioic acid.
The polyamide can also be a product of the condensation of a dicarboxylic acid and diamine. In this case an excess of the diacid is used to assure the presence of carboxyl ends. The exact ratio of diacid to diamine is chosen to achieve the final desired molar mass of the polyamide hard segment. Linear aliphatic or cycloaliphatic diacids can be used. The preferred dicarboxylic acids contain 4-14 carbon atoms and most preferred are linear aliphatic dicarboxylic acids that contain 4-14 carbon atoms. Examples include succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid. Most preferred is dodecanedioic acid. Linear aliphatic diamines containing 4-14 carbon atoms are preferred. Hexamethylenediamine is most preferred. Examples of polyamides derived from the aforementioned diacids and diamines include nylon 6-6, 6-9, 6-10, 6-12 and 9-6 which are products of the condensation of hexamethylene diamine with adipic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, and of nonamethylene diamine with adipic acid, respectively.
The soft segment of the polytrimethylene ether ester amide is prepared from polytrimethylene ether glycol (PO3G). PO3G""s useful for this invention are described in U.S. patent application Ser. Nos. 09/738,688 and 09/738,689, both filed Dec. 15, 2000 (now U.S. patent application Nos. 2002/0007043 A1 and 2002/0010374 A1), and their PCT counterparts WO 01/44348 and 01/44150, all of which are incorporated herein by reference.
PO3G can be prepared by any process known in the art. PO3G can be prepared by dehydration of 1,3-propanediol or by ring opening polymerization of oxetane. The process is irrelevant so long as the polyether glycol meets the specifications for the final polymer product. Methods for making PO3G are described in U.S. patent application Ser. Nos. 09/738,688 and 09/738,689, both filed Dec. 15, 2000 (now U.S. patent application Nos. 2002/0007043 A1 and 2002/0010374 A1) and their PCT counterparts WO 01/44348 and 01/44150, all of which are incorporated herein by reference.
Up to 60 weight % of the soft segment may comprise polymeric ether glycol other than PO3G. Preferred are those selected from the group consisting of polyethylene ether glycol (PEG), polypropylene ether glycol (PPG), polytetramethylene ether glycol (PO4G), polyhexamethylene ether glycol, and copolymers of tetrahydrofuran and 3-alkyl tetrahydrofuran (THF/3MeTHF). The other polymeric ether glycols have an average molar mass such that the polytrimethylene ether segment containing them has an average molar mass of at least about 800, more preferably at least about 1,000 and more preferably at least about 1,500. Preferably at least about 50 weight %, more preferably at least about 75 weight %, and most preferably about 85 to 100 weight %, of the polyether glycol used to form the soft segment is PO3G.
Small amounts of other repeat units may also be present in the polytrimethylene ether ester amide. Among these other repeat units may be branching agents, which are tri- or higher functional compounds such as triamines, trihydroxy compounds, or tricarboxylic acids, even though these branching agents may change the rheological properties of the resulting polymer. Trifunctional compounds are preferred as branching agents. Examples of useful branching agents include trimesic acid and tris(2-aminoethyl) amine.
The polytrimethylene ether ester amides may be made by known methods, see for instance U.S. Pat. Nos. 4,230,838, 4,331,786, 4,252,920, 4,208,493, 5,444,120 and 6,300,463, and S. Fakirov, et al., Makromol. Chem., vol. 193, p. 2391-2404 (1992), all of which are incorporated by reference. They are preferably prepared by reacting the carboxyl terminated polyamide with the polyalkylene glycol at reduced pressures and temperatures between 200 and 280xc2x0 C., and in the presence of a catalyst. Pressure is typically in the range of about 0.01 to about 18 mm Hg (1.3 to 2400 Pa), preferably in the range of about 0.05 to about 4 mm Hg (6.7 to 533 Pa) and most preferably about 0.05 to about 2 mm Hg (6.7 to 267 Pa). Examples of suitable catalysts include tin catalysts such as butylstannoic acid, titanium catalysts such as tetraalkylorthotitanate (e.g., tetrabutyl or tetraisopropyl titanate), or zirconate catalysts such as tetrabutylzirconate. Tetrabutylzirconate is preferred.
Polytrimethylene ether ester amides are useful wherever thermoplastic elastomers are used. They are particularly useful in making fibers, fabrics, films and other shaped articles, such as molding resins for automotive and electrical uses (including glass and other fiber reinforced molding resins). The fibers are stretchy and have excellent physical properties, including superior strength, elongation and stretch recovery properties, particularly improved unload power. Typically they have much higher enlongation and much better elastic recovery (lower tensile set) after stretching than similar polymers based on other polyether glycols, especially when recovering from higher elongations such as 200% or more. These polymers also exhibit a high level of elongation while maintaining a high level of tenacity. This is particularly important when used as the elastic fibers in fabrics such as undergarments and bathing suits.
The fibers can include monocomponent and multicomponent fiber (containing the polyether ester amide as at least one component) such as bicomponent and biconstituent fibers (for example, as described in U.S. patent application Ser. No. 09/966,145, filed Sep. 28, 2001 and U.S. patent application Ser. No. 09/966,037, filed Sep. 28, 2001), which are incorporated herein by reference, and can be continuous filaments or staple fiber. The fibers are used to prepare woven, knit and nonwoven fabric. The nonwoven fabrics can be prepared using conventional techniques such as use for meltblown, spunbonded and card and bond fabrics, including heat bonding (hot air and point bonding), air entanglement, etc.
Fibers and fabrics may be made by standard methods such as described in H. Mark, et al., Ed., Encyclopedia of Polymer Science and Engineering, Vol. 6, John Wiley and Sons, New York, 1986, pages 733-755 and 802-839, and U.S. Pat. Nos. 4,331,786, 5,489,667 and 6,300,463, all of which are incorporated herein by reference or by other well known methods.
The fibers are preferably at least about 10 denier (11 dtex), and preferably are up to about 2,000 denier (2,200 dtex), more preferably up to about 1,200 denier (1,320 dtex), and most preferably up to about 120 denier (132 dtex).
Spinning speeds can be at least about 200 meters/minute (m/min), more preferably at least about 400 m/min, and ever more preferably at least about 500 m/min, and can be up to about 2,000 or about 3,000 m/min or higher.
In most cases it is preferred not to draw the fibers. However, the fibers can be drawn and when drawn draw ratios preferably range from about 1.5xc3x97 to about 6xc3x97, more preferably at least about 1.5xc3x97 and more preferably up to about 4xc3x97. Single step draw is the preferred drawing technique.
Finishes can be applied for spinning or subsequent processing, and include silicon oil, mineral oil, and other spin finishes used for polyether ester amide elastomers.
Conventional additives can be incorporated into the polytrimethylene ether ester amides, polytrimethylene ether glycol, polyamide or fiber by known techniques. The additives include delusterants (e.g., TiO2, zinc sulfide or zinc oxide), colorants (e.g., dyes), stabilizers (e.g., antioxidants, ultraviolet light stabilizers, heat stabilizers, etc.), fillers, flame retardants, pigments, antimicrobial agents, antistatic agents, optical brightners, extenders, processing aids, viscosity boosters, and other functional additives.